<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>

<body style="background-color:white;">
  <!-- 这是容器 -->
  <div id="app"></div>
</body>
<!-- <script>
  var str = 'border-left-color'

  var str1 = str.split('-')
  for(var i = 0;i<str1.length;i++){
    str1[i].toLowerCase()
    
    
  }
  console.log(str[i]);
  

</script> -->
</html>